• 제어로봇시스템학회논문지
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• 제5권1호
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• pp.1-10
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• 1999

We consider the problem of synthesizing an internally stabilizing linear time-invariant controller for a linear tune-Invariant plant such that a given closed loop transfer function is strictly sector bounded. We show that the standard $H{\infty}$ control problem and the $\tau$ -positive real control problem are special cases of sector bounded control problem. Necessary and sufficient conditions for the existence of a controller are obtained. The state-space representation for strictly proper controllers are given in terms of solutions to ARIs or AREs.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.754-758
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• 1996

In this paper, a new method of position synchronizing control is proposed for multi-axes driving system. The proposed synchronizing control system is constituted with speed and synchronizing controller. The structure of synchronizing control system is varied by sign of synchronizing error. When a disturbance input becomes added to one axis, this axis becomes slave axis. The other axis is master axis. Therefore, master axis is not influenced by the disturbance. The speed controller of the first axis is designed by $H_{\infty}$ control theory. The speed controller of the second axis is designed by inverse dynamics of speed control system of the first axis. The speed control system designed with $H_{\infty}$ controller guarantees low sensitivity for the disturbance as well as robustness against model uncertainties. Especially, the synchronizing controller is designed to keep position error to minimize by controlling speed of slave axis. The effectiveness of the proposed method is successfully confirmed through several experiments.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.112-112
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• 2000

The aim of this paper is to design a two degree-of-freedom H$_{\infty}$ controller for lateral control of the vehicle. The object of this controller is to track the centerline of the reference lane. The controller is splited into two parts, feedback and prefilter. The feedback part is for both robust stability and disturbance attenuation, while the prefilter is for improving the robust tracking properties of closed loop system. This paper is consist of preface, background theory, dynamics of vehicle, controller design and computer simulation.ter simulation.

• 제어로봇시스템학회논문지
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• 제6권7호
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• pp.578-585
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• 2000

This paper presents a robust and systematic bilateral controller design method for a teleoperation of an underwater manipulator. Disturbance observer is used as a local controller of the master and underwater slave manipulator to set up the teleoperation system as a nominal model by compensating coupled nonlinear terms model uncertainties and external disturbances in the water. Using the linearized master/slave model a $H_{\infty}$ optimal control scheme is applied to systematically construct a force reflecting bilateral controller.

• 한국자동차공학회논문집
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• 제9권3호
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• pp.92-99
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• 2001

This paper presents a simulation study using a robust controller to improve the roll stability of a vehicle. The controller is designed in the framework of an output feedback H$_{\infty}$ control scheme based on the 3DOF linear vehicle model, solving the mixed-sensitivity problem to guarantee the robust stability and disturbance rejection with respect to parameter variations due to laden and running vehicle conditions. In order to investigate the feasibility of the active roll control system in a real car, its performance is evaluated by simulation in a 10DOF full vehicle model with actuator dynamics and tire characteristics.

• 한국군사과학기술학회지
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• 제5권1호
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• pp.75-82
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• 2002

In this paper, the robust PID(Proportional-Integral-Derivative) controller was designed for speed control of BLDC motors using the frequency region model matching method. It was designed the robust PID controller satisfying disturbance attenuation and robust tracking performance using an H$\infty$ control method. The robust PID controller gains with the performances of the designed H$\infty$ controller are determined using the model matching method at frequency domain. Consequently, simulation results show that the proposed PID speed controller satisfies load torque disturbance attenuation and robust tracking performance, and this study has usefulness and applicability for the speed control system design of BLDC motors.

• 한국가스학회지
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• 제3권2호
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• pp.62-69
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• 1999

본 논문에서는 혼합감도문제를 이용하여 강인한 서보계를 구성함으로서 동위치 제어 시스템의 제어계를 설계하는 방법을 제안하였고, LQG를 이용한 다변수 디지털 서보 제어기 및 H$\infty$ 최적 제어기와의 비교실험을 통하여 제안된 제어기의 유용성을 입증하였다.

• 제어로봇시스템학회논문지
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• 제14권7호
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• pp.615-623
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• 2008

This paper proposes an $H_{\infty}$ controller design method for Takagi-Sugeno (T-S) fuzzy systems using a fuzzy basis-function-dependent Lyapunov function. Sufficient conditions for the guaranteed $H_{\infty}$ performance of the T-S fuzzy control system are given in terms of linear matrix inequalities (LMIs). These LMI conditions are further used for a convex optimization problem in which the $H_{\infty}-norm$ of the closed-loop system is to be minimized. To facilitate the basis-function-dependent Lyapunov function approach and thus improve the closed-loop system performance, additional decision variables are introduced in the optimization problem, which provide an additional degree-of-freedom and thus can enlarge the solution space of the problem. Numerical examples show the effectiveness of the proposed method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.52-55
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• 1996

In this paper, we consider the decentralized reduced-order H$_{\infty}$ controller for the general plant. Simplifying method is suggested for the general plant with the decentralized controller structure. When the controller is reconstructed for the original system, the decentralizability of the controller for the transformed system is generally destroyed with the older method. We solve this problem. For the simplified system, the structure of the decentralized controller is suggested..

• 전자공학회논문지SC
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• 제39권3호
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• pp.183-190
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• 2002

본 논문에서는 구조화된 어파인(affine) 파라미터 불확실성을 가지는 시변 선형시스템과 구조적 불확실성을 가지는 상태궤환 제어기에 대한 견실 비약성 H∞ 제어기 설계방법을 다루었다. 또한 견실 비약성 H∞ 제어기가 존재할 충분조건, 제어기 설계방법 및 비약성을 만족하는 제어기의 꽉찬 집합(compact set)을 제시하였다. 이 때 제시한 조건은 변수치환과 슈어 여수(Schur complement)정리를 통하여 선형행렬부등식 (LMI : Linear Matrix Inequality)의 계수가 꽉찬 집합 내의 파라미터의 함수로 정의되는 파라미터화 선형 행렬부등식(PLMls: parameterized Linear Matrix Inequalities)으로 표현되므로 분리 볼록개념 (separated convexity concepts)에 기초한 완화기법을 이용하여 유한개의 LMI로 변환하였다. 그리고 본론문에서 제시한 견실 비약성 H∞ 제어기가 제어기이득의 변화에도 불구하고 폐루프시스템의 점근적 안정성 (asymptotic stability)과 외란감쇠 성능을 보장함을 보였다.